INFO: task kworker/u4:3:204 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:3 D24944 204 2 0x80000000 Workqueue: writeback wb_workfn (flush-7:4) Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1016 [inline] __mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078 f2fs_balance_fs+0x709/0xd80 fs/f2fs/segment.c:512 f2fs_write_inode+0x500/0x600 fs/f2fs/inode.c:630 write_inode fs/fs-writeback.c:1244 [inline] __writeback_single_inode+0x733/0x11d0 fs/fs-writeback.c:1442 writeback_sb_inodes+0x537/0xef0 fs/fs-writeback.c:1647 __writeback_inodes_wb+0xc6/0x280 fs/fs-writeback.c:1716 wb_writeback+0x841/0xcc0 fs/fs-writeback.c:1822 wb_check_old_data_flush fs/fs-writeback.c:1924 [inline] wb_do_writeback fs/fs-writeback.c:1977 [inline] wb_workfn+0x8ba/0x1250 fs/fs-writeback.c:2006 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 4 locks held by kworker/u4:3/204: #0: 0000000008b84d39 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000f6132c6b ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 000000001e354c02 (&type->s_umount_key#59){++++}, at: trylock_super+0x1d/0x100 fs/super.c:412 #3: 0000000036cd922d (&sbi->gc_mutex){+.+.}, at: f2fs_balance_fs+0x709/0xd80 fs/f2fs/segment.c:512 1 lock held by khungtaskd/1571: #0: 00000000009604bc (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by kworker/1:1H/2837: #0: 0000000080fce099 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1826 [inline] #0: 0000000080fce099 (&rq->lock){-.-.}, at: __schedule+0x1f9/0x2040 kernel/sched/core.c:3455 1 lock held by in:imklog/7804: #0: 000000000c70009c (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 3 locks held by kworker/u4:11/12846: 2 locks held by syz-executor.4/19414: 2 locks held by syz-executor.0/20611: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/20614: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/20615: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/20616: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/20640: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/20641: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/21050: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/21051: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/21052: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 2 locks held by syz-executor.0/21053: #0: 000000001e354c02 (&type->s_umount_key#59){++++}, at: iterate_supers+0xdb/0x290 fs/super.c:631 #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:338 [inline] #1: 00000000fbe95c5d (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0x9a0 fs/fs-writeback.c:2457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1571 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11821 Comm: kworker/u4:8 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Workqueue: phy13 ieee80211_iface_work RIP: 0010:unwind_next_frame+0xf2a/0x1400 arch/x86/kernel/unwind_orc.c:555 Code: ff ff e8 23 ad d6 ff e9 86 f1 ff ff 49 8d 7f 02 48 be 00 00 00 00 00 fc ff df 49 8d 56 40 48 89 f8 48 c1 e8 03 44 0f b6 04 30 <49> 8d 47 03 49 89 c1 49 c1 e9 03 41 0f b6 34 31 49 89 f9 41 83 e1 RSP: 0018:ffff888048b96f38 EFLAGS: 00000a02 RAX: 1ffffffff171fac8 RBX: 1ffff11009172df0 RCX: ffffffff8b8fd645 RDX: ffff888048b97160 RSI: dffffc0000000000 RDI: ffffffff8b8fd642 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8b8fd628 R10: ffff888048b9717f R11: 0000000000074071 R12: ffff888048b971b0 R13: ffff888048b97155 R14: ffff888048b97120 R15: ffffffff8b8fd640 FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb6c3d45718 CR3: 00000000b2ad9000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x5b8/0x960 arch/x86/kernel/unwind_orc.c:667 unwind_start arch/x86/include/asm/unwind.h:60 [inline] __save_stack_trace+0x72/0x190 arch/x86/kernel/stacktrace.c:43 save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553 __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] kzalloc include/linux/slab.h:709 [inline] cfg80211_inform_bss_frame_data+0x200/0xeb0 net/wireless/scan.c:1255 ieee80211_bss_info_update+0x42d/0x1800 net/mac80211/scan.c:105 ieee80211_rx_bss_info net/mac80211/ibss.c:1125 [inline] ieee80211_rx_mgmt_probe_beacon+0xb4f/0x15c0 net/mac80211/ibss.c:1607 ieee80211_ibss_rx_queued_mgmt+0xe27/0x18b0 net/mac80211/ibss.c:1634 ieee80211_iface_work+0x5c4/0x8a0 net/mac80211/iface.c:1341 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415